Letrozole plus misoprostol versus misoprostol alone in the induction of anembryonic missed abortion: a randomized controlled trial conducted in Upper Egypt

Abstract

Background: A missed abortion is a spontaneous abortion in which the embryo or fetus has already died but has remained in the uterus for days or weeks with a closed cervical ostium. Termination of pregnancy could be achieved either by surgical evacuation or medical or expectant management. Letrozole is a third-generation aromatase inhibitor. According to many recent studies, letrozole given for three days before the administration of misoprostol was more effective than misoprostol alone at inducing abortion. Our study compared the efficacy of various letrozole regimens (10 mg/d for three days and a single dose of 20 mg) combined with misoprostol vs. misoprostol alone in inducing abortion. To find the most efficient regimen of letrozole administered before misoprostol to induce an abortion. Methodology: This prospective, parallel, three-arm, single-blinded, allocation-concealed randomized controlled trial was conducted in Sohag Teaching Hospital in Upper Egypt. We randomly divided 105 patients with anembryonic missed abortion (up to 63 days gestation) with no history of medical disorders or a history of allergies to misoprostol or letrozole into three equal groups (a single-dose letrozole group, a multiple-dose letrozole group, and a misoprostol-only group). The complete abortion rate, incomplete abortion rate, failure to abort rate, and induction-to-abortion interval were all collected. All statistical calculations were performed using the computer program SPSS (Statistical Package for the Social Science, SPSS Inc., Chicago, IL, USA). Results: The complete abortion rate was significantly higher in the single-dose letrozole and multiple-dose letrozole groups than in the misoprostol group (p values = 0.0455 and 0.001, respectively). On the other hand, there was no significant difference in the complete abortion rate between the single-dose group and the multiple-dose letrozole group (p-value = 0.1713). The time to complete abortion was significantly shorter in the single-dose and multiple-dose letrozole groups than in the misoprostol group (p values = 0.0036 and 0.0049, respectively). On the other hand, there was no significant difference in the time to complete abortion between the single-dose letrozole group and the multiple-dose letrozole group (P = 0.532). Conclusion: Single- and multiple-dose letrozole regimens followed by misoprostol had a higher rate and a shorter time to complete abortion than misoprostol alone. Trial registration: The trial is registered at gov with the name “letrozole and abortion” and the identifier “NCT05198050”. The date of registration was April 1, 2022, registered prospectively. URL: https://register.clinicaltrials.gov/prs/app/action/ViewOrUnrelease?uid=U0004GED&ts=25&sid=S000BPDQ&cx=43mobl .